Let's roll up our sleeves and solve this. We have 605 and we're going to multiply it by 3, essentially adding 605 to itself 3 times.
Step 1: 0 + 605 = 605
Step 2: 605 + 605 = 1210
Step 3: 1210 + 605 = 1815

So, 605*3 = 1815